Powder recovery container and image forming apparatus

ABSTRACT

A powder recovery container includes a reservoir chamber that stores a recovered powder; a recovery port that faces the reservoir chamber, a powder conveying unit that conveys and recovers the powder through the recovery port being removably inserted into the recovery port; a pair of door panels having rotating shafts arranged at two positions with the recovery port arranged therebetween, the door panels being rotated toward the reservoir chamber around the rotating shafts to open and close the recovery port; sealing members attached to the door panels, the sealing members overlapping one another between distal ends of the door panels to seal a gap between the distal ends of the door panels when the door panels are located at positions, at which the recovery port is closed; and urging members that urge the door panels in a direction, in which the recovery port is closed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC 119 fromJapanese Patent Application No. 2009-248675 filed Oct. 29, 2009.

BACKGROUND

(i) Technical Field

The present invention relates to a powder recovery container and animage forming apparatus.

(ii) Related Art

In an image forming apparatus, such as an electrophotographic copier ora laser beam printer, a toner image developed on a photoconductor drumis transferred on a recording sheet, and then a cleaner removes aremaining toner adhering to the photoconductor drum. The removedremaining toner is recovered as a waste toner (a used powder) in awaste-toner recovery box (a powder recovery container) in the imageforming apparatus.

In recent years, there is a color image forming apparatus that obtains acolor image such that toner images with plural colors formed by pluralimage forming engines are first transferred from photoconductor drumsonto an intermediate transfer belt, and then are second transferred fromthe intermediate transfer belt onto a recording sheet. In the case ofthe color image forming apparatus, the photoconductor drums and cleanersthat clean the photoconductor drums are provided respectively for, forexample, image forming engines of yellow, cyan, magenta, and black.Waste toners have to be recovered from the cleaners of the four imageforming engines. After the toner image is second transferred from theintermediate transfer belt onto the recording sheet, a remaining toneradhering to the intermediate transfer belt has to be cleaned. A cleaneris also provided for the intermediate transfer belt. Thus, in the caseof the color image forming apparatus, the waste toners from the pluralcleaners are recovered in the waste-toner recovery box.

The waste-toner recovery box is an expendable supply. When thewaste-toner recovery box is full, the waste-toner recovery box istypically replaced with an empty waste-toner recovery box.

SUMMARY

According to an aspect of the invention, there is provided a powderrecovery container including a container body having a wall surface; areservoir chamber that stores a recovered powder; a recovery port thatfaces the reservoir chamber, a powder conveying unit that conveys andrecovers the powder through the recovery port being removably insertedinto the recovery port; a pair of door panels having rotating shaftsarranged at two positions with the recovery port arranged therebetween,the door panels being rotated toward the reservoir chamber around therotating shafts to open and close the recovery port; sealing membersattached to the door panels, the sealing members overlapping one anotherbetween distal ends of the door panels to seal a gap between the distalends of the door panels when the door panels are located at positions,at which the recovery port is closed; and urging members that urge thedoor panels in a direction, in which the recovery port is closed.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiment(s) of the present invention will be described indetail based on the following figures, wherein:

FIG. 1 briefly illustrates a configuration of a printer having awaste-toner recovery box according to an exemplary embodiment of theinvention attached to the printer;

FIG. 2 briefly illustrates an arranged position of the waste-tonerrecovery box in the printer shown in FIG. 1;

FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2;

FIG. 4 is a perspective view showing the waste-toner recovery boxaccording to the exemplary embodiment of the invention when viewed froma front surface;

FIG. 5 is a perspective view showing the waste-toner recovery boxaccording to the exemplary embodiment of the invention when viewed froma rear surface;

FIG. 6 is a perspective view showing the inside of a front cover that isa component of the waste-toner recovery box according to the exemplaryembodiment of the invention;

FIG. 7 is a perspective view showing the inside of a rear cover that isa component of the waste-toner recovery box according to the exemplaryembodiment of the invention;

FIG. 8 is a perspective view showing an inner structure of thewaste-toner recovery box according to the exemplary embodiment of theinvention when viewed from the rear;

FIG. 9 is a perspective view showing an inner structure of thewaste-toner recovery box according to the exemplary embodiment of theinvention when viewed from the front;

FIG. 10 is a cross-sectional view taken along line X-X in FIG. 4;

FIG. 11 is a cross-sectional view showing a specific part taken alongline XI-XI in FIG. 10;

FIG. 12 is a perspective view showing a pipe that is a component of thewaste-toner recovery box according to the exemplary embodiment of theinvention when viewed from the lower front;

FIG. 13 is a cross-sectional view taken along the diameter of the pipeshown in FIG. 12;

FIG. 14 is a perspective view showing an area around a recovery port ofthe waste-toner recovery box according to the exemplary embodiment ofthe invention when viewed from the outside;

FIG. 15 is a perspective view showing the area around the recovery portof the waste-toner recovery box according to the exemplary embodiment ofthe invention when viewed from the outside when a plate is attached;

FIG. 16 is a perspective view showing the area around the recovery portof the waste-toner recovery box according to the exemplary embodiment ofthe invention when viewed from the inside;

FIG. 17 briefly illustrates shutters attached to the recovery port ofthe waste-toner recovery box according to the exemplary embodiment ofthe invention;

FIG. 18 is a cross-sectional view showing the area around the recoveryport of the waste-toner recovery box according to the exemplaryembodiment of the invention;

FIG. 19 is a view when the shutters are at positions, at which therecovery port is closed, in the waste-toner recovery box according tothe exemplary embodiment of the invention;

FIG. 20 is a view when the shutters are at positions, at which therecovery port is opened, in the waste-toner recovery box according tothe exemplary embodiment of the invention;

FIG. 21 illustrates a specific part in FIG. 19; and

FIG. 22 illustrates a specific part in FIG. 20.

DETAILED DESCRIPTION

An exemplary embodiment as an example of the present invention will bedescribed in detail below with reference to the attached drawings. Inthe drawings for describing the exemplary embodiment, the same referencesigns are basically applied to equivalent components, and the redundantdescription is omitted.

Referring to FIG. 1, a tandem-type color laser beam printer 1 (anexample of an image forming apparatus) having a waste-toner recovery boxattached to the printer 1 includes four image forming engines 10Y, 10M,10C, and 10K that form toner images of colors including yellow, magenta,cyan, and black. The printer 1 also includes an intermediate transferbelt 20. The toner images from the image forming engines 10Y, 10M, 10C,and 10K are transferred on the intermediate transfer belt 20 in asuperposed manner (first transfer). The toner images transferred on theintermediate transfer belt 20 in a superposed manner are transferred ona recording sheet P (second transfer), and hence a full-color image isformed.

The intermediate transfer belt 20 is an endless belt and wound around apair of belt conveying rollers 21 and 22. The intermediate transfer belt20 receives the first transfer of the toner images formed by the imageforming engines 10Y, 10M, 10C, and 10K of the respective colors whilethe intermediate transfer belt 20 is rotated in a direction indicated byan arrow in FIG. 1.

A second transfer roller 30 is provided at a position to face the onebelt conveying roller 21 with the intermediate transfer belt 20 arrangedtherebetween. The recording sheet P passes through a portion between thesecond transfer roller 30 and the intermediate transfer belt 20 thatmutually contact one another with a pressure, and receives the secondarytransfer of the toner images from the intermediate transfer belt 20. Abelt cleaner 23 for the intermediate transfer belt 20 is arranged at aposition to face the other belt conveying roller 22. The belt cleaner 23removes the toner remaining on and adhering to the intermediate transferbelt 20 after the second transfer, from the intermediate transfer belt20. The remaining toner removed by the belt cleaner 23 is conveyed as awaste toner to the front (a near side in FIG. 1) by a conveying shaft 23a that includes a spiral blade, and is recovered in a waste-tonerrecovery box (described later).

The four image forming engines 10Y, 10M, 10C, and 10K are arranged inparallel below the intermediate transfer belt 20. The image formingengines 10Y, 10M, 10C, and 10K first transfer the toner images that areformed in accordance with image information of the respective colorsonto the intermediate transfer belt 20. The four image forming engines10Y, 10M, 10C, and 10K are arranged in order of yellow, magenta, cyan,and black in a rotation direction of the intermediate transfer belt 20.The black-image forming engine 10K that is generally the most frequentlyused is arranged nearest the second transfer position.

A raster scanning unit 40 is provided below the image forming engines10Y, 10M, 10C, and 10K. The raster scanning unit 40 exposesphotoconductor drums 11 of the respective image forming engines 10Y,10M, 10C, and 10K with light in accordance with image information. Theraster scanning unit 40 is common to all the image forming engines 10Y,10M, 10C, and 10K, and includes four semiconductor lasers (not shown)that emit laser beams L that are modulated in accordance with the imageinformation of the respective colors, and a polygonal mirror 41 thatrotates at a high speed and causes the laser beams L to axially scan thephotoconductor drums 11. The laser beams L from the polygonal mirror 41are reflected by mirrors (not shown) and propagate in predeterminedpaths. The photoconductor drums 11 of the image forming engines 10Y,10M, 10C, and 10K are exposed with the laser beams L through scanningwindows 42 provided in an upper portion of the raster scanning unit 40.

Each of the image forming engines 10Y, 10M, 10C, and 10K includes thephotoconductor drum 11, a charging roller 12 that electrically chargesthe surface of the photoconductor drum 11 to have a predeterminedpotential, a developing unit 13 that develops an electrostatic latentimage formed on the photoconductor drum 11 by the exposure with thelaser beam L and forms a toner image, and a drum cleaner 14 that removesa remaining toner and paper dust from the surface of the photoconductordrum 11 after the toner image is transferred on the intermediatetransfer belt 20. The toner images in accordance with the imageinformation of the respective colors are formed on the photoconductordrums 11.

In the printer 1 according to this exemplary embodiment, the developingunit 13 uses a two-component powder containing a toner and a carrier. Toomit maintenance work for exchanging the powder deteriorated with time,a trickle development system is used in which the powder containing thetoner and the carrier is supplied from a supply cartridge (not shown),and the deteriorated powder is automatically exhausted.

Each developing unit 13 is supplied with a new powder from the rear (afar side in FIG. 1) of a conveying shaft 13 a including a spiral bladelike the conveying shaft 23 a. A remaining toner removed by each drumcleaner 14 is exhausted as a waste toner to the front by a conveyingshaft (not shown). The waste toner exhausted from the drum cleaner 14 isrecovered in a waste-toner recovery box (described later).

Exemplary powders to be recovered according to this exemplary embodimentare waste toners including used toners exhausted from the drum cleaners14 and a used toner exhausted from the belt cleaner 23. For example, arecovery box that recovers the carrier and the toner exhausted from thedeveloping unit 13, or a recovery box that recovers only the used tonersexhausted from the drum cleaners 14 may be used.

First transfer rollers 15Y, 15M, 15C, and 15K are provided at positionsto face the photoconductor drums 11 of the image forming engines 10Y,10M, 10C, and 10K with the intermediate transfer belt 20 arrangedtherebetween. When transfer bias voltages are applied to the transferrollers 15Y, 15M, 15C, and 15K, electric fields are formed between thephotoconductor drums 11 and the transfer rollers 15Y, 15M, 15C, and 15K.The toner images on the photoconductor drums 11 with electric chargesare transferred on the intermediate transfer belt 20 by Coulomb forces.

Meanwhile, the recording sheet P is transported from a sheet feedcassette 2 accommodated in a lower portion of the printer 1, to theinside of a housing, and more particularly to the second transferposition at which the intermediate transfer belt 20 contacts the secondtransfer roller 30. To set the sheet feed cassette 2, the sheet feedcassette 2 is pushed into the printer 1 from the front of the printer 1.A pickup roller 24 and a sheet feed roller 25 are provided above the setsheet feed cassette 2. The pickup roller 24 picks up the recording sheetP in the sheet feed cassette 2. Also, a retard roller 26 is provided ata position to face the sheet feed roller 25. The retard roller 26prevents double feeding of recording sheets P.

A transport path 27 for the recording sheet P in the printer 1 isprovided in a vertical direction along a left side surface of theprinter 1. The recording sheet P picked from the sheet feed cassette 2located at the bottom of the printer 1 is elevated in the transport path27. A registration roller 29 controls an entry timing of the recordingsheet P and introduces the recording sheet P to the second transferposition. The toner images are transferred on the recording sheet P atthe second transfer position. Then, the recording sheet P is sent to afixing unit 3 provided in an upper portion of the printer 1. The fixingunit 3 fixes the toner images to the recording sheet P. An output roller28 outputs the recording sheet P with the fixed toner images, on a sheetoutput tray 1 a provided on an upper surface of the printer 1, in astate in which an image formed surface of the recording sheet P facesthe lower side.

When a full-color image is formed by the color laser beam printer 1 withsuch a configuration, the raster scanning unit 40 exposes thephotoconductor drums 11 of the image forming engines 10Y, 10M, 10C, and10K with light in accordance with the image information of therespective colors at a predetermined timing. Accordingly, electrostaticlatent images are formed on the photoconductor drums 11 of the imageforming engines 10Y, 10M, 10C, and 10K in accordance with the imageinformation. By supplying the electrostatic latent images with thetoners, the toner images are formed.

The toner images formed on the photoconductor drums 11 of the imageforming engines 10Y, 10M, 10C, and 10K are successively transferred onthe rotating intermediate transfer belt 20. Thus, the multiple tonerimages, in which the toner images of the respective colors aresuperposed on one another, are formed on the intermediate transfer belt20. Meanwhile, the recording sheet P is sent from the sheet feedcassette 2 and passes through the portion between the second transferroller 30 and the intermediate transfer belt 20 at a proper timing atwhich the toner images which have been first transferred on theintermediate transfer belt 20 reach the second transfer position.Accordingly, the multiple toner images on the intermediate transfer belt20 are second transferred on the recording sheet P. The fixing unit 3fixes the second transferred toner images to the recording sheet P.Thus, the image formation of a full-color image on the recording sheet Pis completed.

In the printer 1 according to this exemplary embodiment having such aconfiguration, all the waste toners exhausted from the belt cleaner 23and the respective drum cleaners 14 are recovered in a singlewaste-toner recovery box 50 (an example of a powder recovery container).

Referring to FIGS. 2 and 3, the waste-toner recovery box 50 is providedat the front of the image forming engines 10Y, 10M, 10C, and 10K ofyellow, magenta, cyan, and black that are arranged in parallel. Thewaste-toner recovery box 50 is provided at a position slightly below theimage forming engines 10Y, 10M, 10C, and 10K. The waste toners exhaustedfrom the drum cleaners 14 to the front are recovered in the waste-tonerrecovery box 50. The waste toner removed from the intermediate transferbelt 20 by the belt cleaner 23 is also recovered in the waste-tonerrecovery box 50.

Referring to FIGS. 4 to 7, the waste-toner recovery box 50 includes afront cover 51 and a rear cover 52 made of plastic. The front and rearcovers 51 and 52 are combined and hence define a container body 50 a.The container body 50 a has spaces therein. The waste-toner recovery box50 is long in the width direction. The thickness of the waste-tonerrecovery box 50 is smaller than the length thereof in the verticaldirection. The length in the width direction of the waste-toner recoverybox 50 is longer than a length from the drum cleaner 14 for theblack-image forming engine 10K to the belt cleaner 23. When thewaste-toner recovery box 50 is attached to the printer 1, thewaste-toner recovery box 50 is located at the front of the image formingengines 10Y, 10M, 10C, and 10K and the belt cleaner 23. Thus, the wastetoner is directly dropped into the inner space (the reservoir chamber61).

Referring to FIGS. 4, 5, and 6, lock pieces 53 are provided at twopositions of an upper portion of the front cover 51. Each lock piece 53has a free end facing the front, and has an upper surface 53 a and aprotrusion 54 on the upper surface 53 a. The lock piece 53 iselastically deformable such that the upper surface 53 a is verticallymoved. Also, holes 55 are formed directly below the lock pieces 53. Eachhole 55 is open to the front and has a size that allows several fingersto enter the hole 55. Further, the front cover 51 includes plate pieceattachments 57 at two positions of a lower portion of the front cover51. Plate pieces 56 protruding downward (FIG. 8) are attached to theplate piece attachments 57.

When the waste-toner recovery box 50 is attached to the printer 1, theplate pieces 56 are inserted into grooves (not shown) formed at theprinter 1. The waste-toner recovery box 50 is raised while the insertedportions serve as supporting points. Then, the lock pieces 53 are fittedinto fixing holes (not shown) formed at the printer 1 while the lockpieces 53 are elastically deformed. When the waste-toner recovery box 50is detached from the printer 1, thumbs are hooked at the free ends ofthe lock pieces 53, and the other fingers are inserted into the holes55. The lock pieces 53 are tilted forward while the lock pieces 53 arepushed down with the thumbs, so that the protrusions 54 are releasedfrom the fixing holes. Then, the waste-toner recovery box 50 is liftedobliquely upward.

The waste-toner recovery box 50 is detached from the printer 1, forexample, when the waste-toner recovery box 50 is full or needs to bereplaced because the intermediate transfer belt unit has to be replaced,or because the image forming engines 10Y, 10M, 10C, and 10K located atthe deeper side with respect to the waste-toner recovery box 50 have tobe replaced.

Referring to FIGS. 5 and 7, the rear cover 52 has five recovery ports 58at an upper portion of the rear cover 52. The recovery ports 58 are forthe waste toners that are exhausted from the drum cleaners 14 of theimage forming engines 10Y, 10M, 10C, and 10K. When the waste-tonerrecovery box 50 is attached to the printer 1, coupling pipes (FIG. 20,an example of powder conveying units) that protrude from the drumcleaners 14 of the image forming engines 10Y, 10M, 10C, and 10K and thebelt cleaner 23 to the front are removably inserted into the recoveryports 58. When the coupling pipes 74 that convey the recovered wastetoners are inserted into the recovery ports 58, the waste tonersexhausted from the drum cleaners 14 of the trickle system and conveyedthrough the coupling pipes 74 are dropped into the waste-toner recoverybox 50. The five recovery ports 58 correspond to the drum cleaner 14 ofblack, the drum cleaner 14 of cyan, the drum cleaner 14 of magenta, thedrum cleaner 14 of yellow, and the belt cleaner 23 in order from theright side in FIG. 5.

As described above, the waste-toner recovery box 50 is provided on oneside of the parallel arranged image forming engines 10Y, 10M, 10C, and10K and the belt cleaner 23, so as to cover these components. Thus, thewaste toners exhausted from the image forming engines 10Y, 10M, 10C, and10K and the belt cleaner 23 are directly dropped into the waste-tonerrecovery box 50.

Referring to FIG. 8, shutters 59 (an example of door panels) areprovided at the recovery ports 58. A pair of the shutters 59 has adouble-panel structure that opens left and right from the center. Theshutters 59 are openably and closably attached to the inside of the rearcover 52. The shutters 59 have torsion springs 60 (an example of urgingmembers) that press the shutters 59 to the wall surface of the rearcover 52 and close the recovery port 58 (FIG. 9). The torsion springs 60provide spring forces (urging forces) by using restoration of twistedparts of the torsion springs 60. The shutters 59 normally close therecovery port 58 by the spring forces of the torsion springs 60. Wheneach coupling pipe 74 is inserted into the recovery port 58, thecoupling pipe 74 pushes the shutters 59 inward against the springforces, and hence the recovery port 58 is open.

Referring to FIGS. 8 and 9, the waste-toner recovery box 50 formed ofthe front cover 51 and the rear cover 52 has the reservoir chamber 61 inthe waste-toner recovery box 50. The reservoir chamber 61 stores therecovered waste toners. The reservoir chamber 61 is located below therecovery ports 58 facing the reservoir chamber 61. The waste toners aredropped in the reservoir chamber 61 from the coupling pipes 74 insertedinto the recovery ports 58. When the reservoir chamber 61 is filled withthe waste toners (when the quantity of the waste toners reaches astorage limit), the waste-toner recovery box 50 has to be replaced.

A conveying unit 64 is provided in the reservoir chamber 61 and extendsin the longitudinal direction. The conveying unit 64 extends betweenside walls of the reservoir chamber 61 (that is, the conveying unit 64extends between left and right side walls 52 a of the rear cover 52).The waste toners dropped into the reservoir chamber 61 are accumulatedlike hills at positions directly below the recovery ports 58. When thetops of the hills exceed the storage limit of the waste-toner recoverybox 50, the portion exceeding the storage limit is collapsed andconveyed.

One side of the conveying unit 64 is supported by a bearing 65 providedat the side wall 52 a, and a distal end of the one side of the conveyingunit 64 protrudes outside the side wall 52 a. The distal end is a supplyend through which a driving force (a torque) is supplied to theconveying unit 64. A transmission unit 66 is attached to the distal end.The transmission unit 66 includes a transmission gear train (not shown)that transmits a driving force from a drive source (not shown) providedin the printer 1 to the conveying unit 64. When the waste-toner recoverybox 50 is attached to the printer 1, the transmission unit 66 ismechanically coupled with the drive source in the printer 1. Thus, theconveying unit 64 is driven (rotated) by the drive source.

The conveying unit 64 is fabricated by, for example, injection moldingwith synthetic resin. The conveying unit 64 has a rotating shaft 63 anda spiral blade 62 around the rotating shaft 63. The spiral blade conveysthe waste toner. The spiral blade 62 includes a first blade 62 a and asecond blade 62 b whose spiral directions differ from one another. Thespiral directions of the blades 62 a and 62 b are directions in whichthe waste toners are conveyed from both ends of the rotating shaft 63 tothe center.

The blades 62 a and 62 b are lacking in an area between a positiondirectly below the recovery port 58 for the waste toner of yellow Y anda position directly below the recovery port 58 for the waste toner ofmagenta M. The positions define ends of conveyance. When the conveyingunit 64 is rotated, the waste toners accumulated like hills in thereservoir chamber 61 are collapsed and conveyed toward those positions.

The blade for conveying the waste toner does not have to be the spiralblade, and may be plural flat blades provided at an interval. That is,the shape of the blade may be any shape as long as the blade has thefunction of conveying the waste toner.

Referring to FIG. 10, a detection chamber 67 is provided in thewaste-toner recovery box 50. The waste toner exceeding the storage limitof the reservoir chamber 61 enters the detection chamber 67. If thewaste toner is accumulated to a predetermined level in the reservoirchamber 61 (that is, the storage limit of the reservoir chamber 61), thequantity of the waste toner exceeding the level (that is, exceeding thestorage limit) enters the detection chamber 67.

Referring to FIG. 11, the detection chamber 67 has a sensing chamber 67c that is attached to the rear cover 52 and formed of a transparentmember protruding to the outside. When the waste-toner recovery box 50is attached to the printer 1, the sensing chamber 67 c is inserted intoan area between a light-emitting portion and a light-receiving portionof a light transmission sensor 69 that is provided at the printer 1.

Referring to FIG. 10, a guide path 67 b extends from an entrance 67 a ofthe detection chamber 67. The guide path 67 b has an inclined surfacethat is located below the conveying unit 64. The sensing chamber 67 c islocated ahead of the inclined surface. Namely, the sensing chamber 67 cis not arranged directly below the entrance 67 a. Thus, the waste tonerdropped from the reservoir chamber 61 is gradually accumulated in thesensing chamber 67 c because of the inclined surface of the guide path67 b. When the area between the light-emitting portion and thelight-receiving portion of the light transmission sensor 69 is blockedby the waste toner in the sensing chamber 67 c, the signal of the lighttransmission sensor 69 is changed. Accordingly, it is recognized whetherthe waste toner reaches the predetermined level of the reservoir chamber61.

The entrance 67 a of the detection chamber 67 is formed in an area notoccupied by the first blade 62 a or the second blade 62 b of theconveying unit 64, i.e., at a position facing the ends of conveyance.Thus, the waste toner exceeding the storage limit of the reservoirchamber 61 is conveyed to the entrance 67 a of the detection chamber 67by the conveying unit 64.

Referring to FIGS. 12 and 13, a pipe 68 (an example of a hollow member)is arranged at the entrance 67 a of the detection chamber 67. Theconveying unit 64 penetrates through the pipe 68. The pipe 68 has aperipheral wall 68 b serving as a pipe body and an opening 68 a formedin the peripheral wall 68 b. The opening 68 a faces the entrance 67 a ofthe detection chamber 67. The ends of conveyance for the waste tonercorresponding to the area not occupied by the blade 62 a or 62 b arelocated at the opening 68 a of the pipe 68. The waste toner does notenter the detection chamber 67 unless the waste toner passes through thepipe 68. The pipe 68 has a partition wall 68 c that extends downwardfrom the peripheral wall 68 b and that separates the entrance 67 a ofthe detection chamber 67 from the reservoir chamber 61, to prevent thewaste toner from entering the detection chamber 67 through a path otherthan the opening 68 a of the pipe 68.

With this configuration, when the waste toner locally exceeds thestorage limit of the reservoir chamber 61, the excessive waste toner iscollapsed and conveyed to the center of the reservoir chamber 61 by theconveying unit 64. Since the waste toner is collapsed to the portion notoccupied by the spiral blade 62 of the conveying unit 64, a space isfinally left only below the portion not occupied by the spiral blade 62in the reservoir chamber 61. When the space is eliminated because thewaste toner is conveyed by the conveying unit 64, the reservoir chamber61 is filled with the waste toner. That is, the waste toner reaches thestorage limit.

Then, the waste toner exceeding the storage limit is conveyed by theconveying unit 64 and enters into the pipe 68. The waste toner in thepipe 68 enters the detection chamber 67 through the opening 68 a of thepipe 68. The light transmission sensor 69 detects the waste toner in thesensing chamber 67 c. Accordingly, the output signal of the lighttransmission sensor 69 is changed, and it is recognized that thereservoir chamber 61 is full.

If the image forming engines 10Y, 10M, 10C, and 10K are replaced, thewaste-toner recovery box 50 located in front of the image formingengines 10Y, 10M, 10C, and 10K has to be detached. At this time, if thedetached waste-toner recovery box 50 is left in a state in which therotating shaft 63 of the conveying unit 64 is not horizontal (i.e., in astate in which the rotating shaft 63 is tilted or vertically stands),the waste toner in the reservoir chamber 61 may be collapsed and part ofthe waste toner may enter the detection chamber 67 through the entrance67 a unless the pipe 68 is provided. Then, if the waste toner enters thedetection chamber 67 by a quantity of the waste toner that is detectedby the light transmission sensor 69, when the waste-toner recovery box50 is attached to the printer 1, the output signal of the lighttransmission sensor 69 may be changed and it may be erroneouslyrecognized that the reservoir chamber 61 is full although the reservoirchamber 61 is not filled with the waste toner.

Also, dust resulted from the waste toner floats in the reservoir chamber61. The dust is generated mostly when the conveying unit 64 conveys thewaste toner, in particular, when the conveying unit 64 collapses thewaste toner accumulated like hills when the waste toner locally exceedthe storage limit. Hence, if the pipe 68 is not provided, since thegenerated dust is lighter than the waste toner, part of the dust may notbe conveyed by the conveying unit 64 and may float and enter thedetection chamber 67 through the entrance 67 a. If such a staterepeatedly appears, the dust is accumulated in the detection chamber 67by a quantity of the dust that is detected by the light transmissionsensor 69. Then the output signal of the light transmission sensor 69 ischanged, and it is erroneously detected that the reservoir chamber 61 isfull although the reservoir chamber 61 is not filled with the wastetoner.

In contrast, in this exemplary embodiment, the conveying unit 64 havingthe spiral blade 62 penetrates through the pipe 68, the ends ofconveyance face the opening 68 a of the pipe 68, and hence the wastetoner in the reservoir chamber 61 does not enter the detection chamber67 unless the waste toner passes through the pipe 68. The waste tonercollapsed when the waste-toner recovery box 50 is detached, and the dustgenerated when the conveying unit 64 conveys the waste toner are blockedby the pipe 68 and the spiral blade 62 and prevented from entering thedetection chamber 67. Accordingly, the erroneous detection that thewaste-toner recovery box 50 is full is prevented, and detection accuracyis increased.

As shown in FIG. 9 in detail, the conveying unit 64 is rotatablysupported at two positions including the pipe 68 and the supply end (anend of the conveying unit 64 to which the torque is supplied). An endopposite to the supply end is not supported.

With this structure, the noise generated when the conveying unit 64 isrotated is decreased because the supported area is smaller than a casein which the end opposite to the supply end is supported, that is, acase in which the conveying unit 64 is supported at three positions.

Referring to FIG. 14, a plate holder 70 is formed directly below therecovery port 58 in the outer wall of the rear cover 52. The plateholder 70 extends in the lateral direction and both ends of the plateholder 70 are bent upward. Referring to FIG. 15, the plate holder 70holds a plate 72. The plate 72 closes two small windows 52-1 throughwhich upper ends of rotating shafts 71 (described later) of the shutters59 are exposed. The plate 72 has a hole 72-1 with a diameter that isslightly smaller than the outer diameter of the coupling pipe 74 throughwhich the waste toner is conveyed.

As shown in FIG. 16, the shutters 59 have a double-plate structure thatopens left and right from the center. The rotating shafts 71 arearranged at two positions with the recovery port 58 arrangedtherebetween (in this exemplary embodiment, at two positions with therecovery port 58 arranged therebetween in the lateral direction). Theshutters 59 are rotated around the rotating shafts 71 toward thereservoir chamber 61 to open and close the recovery port 58. In thisexemplary embodiment, each shutter 59 is integrally formed with thecorresponding rotating shaft 71. However, the rotating shaft 71 may beprovided separately from the shutter 59. Also, the shutters 59 do nothave to open left and right, and may open up and down.

Both ends of each of the rotating shafts 71 extending in the verticaldirection have small-diameter portions 71 a and 71 b (see FIG. 17)having reduced diameters with steps. Referring to FIGS. 16 and 18, thesmall-diameter portion 71 a at the upper end is rotatably fitted to aclaw 52-2 (an example of a rotating-shaft support member) protruding atthe rear cover 52 to the inside. The small-diameter portion 71 b at thelower end is rotatably fitted to a hole (not shown) in a mount 52-3 (anexample of a rotating-shaft support member) formed at the inside of therear cover 52 and extending in the lateral direction. Since the lowerend of the rotating shaft 71 is fitted to the hole of the mount 52-3,the mount 52-3 also functions as a member that supports the shutter 59through the rotating shaft 71.

Referring to FIG. 16, each shutter 59 has notches 59 a to avoid theshutter 59 from interfering with the claw 52-2 and the mount 52-3 (therotating-shaft support members). If the space for the claw 52-2 and themount 52-3 that support the rotating shaft 71 of the shutter 59 isreduced in the axial direction of the rotating shaft 71, the claw 52-2and the mount 52-3 may interfere with a rotation region of the shutter59. Since the shutter 59 has the notches 59 a as illustrated, theinterference between the shutter 59 and the claw 52-2 or the mount 52-3is avoided.

With this configuration, the distance between the two rotating-shaftsupport members located at both ends of the rotating shaft 71 (in thisexemplary embodiment, the distance between the claw 52-2 at the upperend and the mount 52-3 at the lower end) is decreased. The claw 52-2 andthe mount 52-3 (the rotating-shaft support members) do not protrude, andhence the space around the shutter 59 is saved.

As shown in FIG. 17 in detail, the pair of shutters 59 have films 73 (anexample of sealing members) attached thereto. The films 73 protrude fromdistal ends of the shutters 59. The films 73 overlap one another betweenthe distal ends of the shutters 59 when the shutters 59 are located atpositions, at which the recovery port 58 is closed, to seal a gapbetween the distal ends of the shutters 59 (the gap which is inevitablygenerated on account of the tolerance as long as the shutters 59 have adouble-panel structure).

The film 73 is made of, for example, a polyurethane material. Forexample, the film 73 is bonded to a surface of the shutter 59 thatcontacts a peripheral edge of the recovery port 58 (that is, a surfaceof the shutter 59 that is visually recognizable when the recovery port58 is viewed from the outside) by using a double-faced adhesive tape.The film 73 may be formed of a material other than polyurethane. Thefilm 73 may be bonded to the shutter 59 by a method other than by usingthe double-faced adhesive tape.

Referring to FIG. 17, a first part of the film 73 is shown attached tothe left shutter 59, and a second part of the film 73 is shown attachedto the right shutter 59. Thus, in FIG. 17, a portion 73 a represents anarea in which the two films 73 overlap one another. A portion 73 brepresents an area of the film 73 that is bonded by the double-facedadhesive tape.

Since such shutters 59 have the films 73 provided thereon, the shutters59 have a rotation radius that is smaller than a rotation radius in acase in which only a single shutter 59 opens and closes the recoveryport 58. In addition, the gap that is generated between the distal endsof the shutters 59 when the pair of shutters 59 is used is sealed withthe films 73. Therefore, the length in the depth direction of thewaste-toner recovery box 50 is restricted, and the waste toner isprevented from leaking from the recovery port 58 when the waste-tonerrecovery box 50 is detached.

Further, since the film 73 is bonded to the surface of the shutter 59that contacts the peripheral edge of the recovery port 58, the portionwith a large thickness in which the film 73 is overlapped (the portion73 a in FIG. 17) is pressed to the peripheral edge of the recovery port58 by the spring force of the torsion spring 60. Thus, a large sealingforce is provided as compared with a case in which the film 73 is bondedto a surface opposite to the aforementioned surface. With this reason,the film 73 is desirably bonded to the surface of the shutter 59 thatcontacts the peripheral edge of the recovery port 58. However, the film73 may be bonded to the surface opposite to the aforementioned surface.

Referring to FIGS. 17 and 18, the length of the film 73 along therotating shaft 71 is smaller than the length of the shutter 59, so thatthe film 73 does not protrude from the shutter 59 along the rotatingshaft 71. Accordingly, the film 73 does not contact the claw 52-2 or themount 52-3 that is the member arranged at one of ends of the rotatingshaft 71 and supporting the rotating shaft 71, and hence the film 73does not generate abnormal noise. Also, the double-faced adhesive tapeof the film 73 is not bonded to the claw 52-2 or the mount 52-3, andhence the double-faced adhesive tape does not disturb the opening andclosing operation of the shutter 59.

The upper end of the rotating shaft 71 is fitted to the claw 52-2, andthe lower end thereof is fitted to the hole in the mount 52-3 from theupper side. Therefore, when the rotating shaft 71 integrally formed withthe shutter 59 is attached, the lower end is fitted to the hole in themount 52-3, then the upper end is moved toward the recovery port 58 andtoward the inside of the waste-toner recovery box 50 while the fittedlower end serves as a supporting point, and the upper end is fittedwhile the claw 52-2 is elastically deformed. When the rotating shaft 71is detached, the upper end is moved away from the recovery port 58 andtoward the outside of the waste-toner recovery box 50 while the lowerend of the rotating shaft 71 serves as the supporting point, and theupper end is detached while the claw 52-2 is elastically deformed. Then,the lower end is removed from the hole in the mount 52-3. If a force isapplied to the shutter 59 in a direction toward a wall surface of thecontainer body 50 a, and the shutter 59 is pushed toward the outside ofthe waste-toner recovery box 50, the rotating shaft 71 may be detachedfrom the claw 52-2.

When the shutter 59 is rotated between the position, at which therecovery port 58 is closed, as shown in FIG. 19 and a position, at whichthe recovery port 58 is opened, as shown in FIG. 20 because the couplingpipe 74 is inserted to or removed from the recovery port 58, a force maybe applied to the shutter 59 due to the impact at this time such thatthe shutter 59 is moved to the outside of the waste-toner recovery box50 (a force in a direction indicated by arrow R in FIG. 20).

Owing to this, in this exemplary embodiment, spacers 59 b are providedat two positions at ends of the shutter 59 near the rotating shaft 71.Each spacer 59 b has a fan-like shape along a part of the outerperiphery of the rotating shaft 71. The spacer 59 b faces the wallsurface of the container body 50 a regardless of the position of thespacer 59 b during the opening and closing operation of the shutter 59.Also, the spacer 59 b, or the end of the shutter 59 near the rotatingshaft 71 is located at a position at a smaller distance from the wallsurface of the container body 50 a than a distance of the rotating shaft71 by which the rotating shaft 71 is moved toward the wall surface ofthe container body 50 a to be detached from the claw 52-2.

Accordingly, if the force is applied to the shutter 59 toward the wallsurface of the container body 50 a, the shutter 59 contacts the wallsurface of the container body 50 a and is inhibited from being movedfurther. The rotating shaft 71 is prevented from being detached from theclaw 52-2.

The spacer 59 b in this exemplary embodiment has a fan-like shape,however, the shape of the spacer 59 b may be circular or polygonal alongthe periphery of the rotating shaft 71.

As described above, in this exemplary embodiment, to apply the urgingforce to the shutter 59 so that the shutter 59 closes the recovery port58, the torsion spring 60 is used for using restoration of the twistedpart 60 a.

Referring to FIGS. 21 and 22, the container body 50 a, to which one endof the torsion spring 60 contacts with a pressure, has a protrusion 75.The protrusion 75 maintains a non-contact state between a tip end of thetorsion spring 60 and the container body 50 a when the shutter 59 isrotated. The protrusion 75 has a protruding amount that maintains thenon-contact state between the tip end of the torsion spring 60 and thecontainer body 50 a when the shutter 59 is located at the position, atwhich the recovery port 58 is closed (the position in FIG. 21).

When the shutter 59 is rotated from the position, at which the recoveryport 58 is closed (FIG. 21) to the position, at which the recovery port58 is opened (FIG. 22), a portion between a terminal 60 b of the twistedpart 60 a of the torsion spring 60 near the container body 50 a and acontact position 60 c between the torsion spring 60 and the protrusion75 is slightly bent outward. Then, referring to FIG. 22, the tip end ofthe torsion spring 60 is displaced away from the container body 50 a (inFIG. 22, a displacement S). As long as the protrusion 75 has the aboveprotruding amount, the tip end of the torsion spring 60 does not contactthe container body 50 a regardless of the rotated position of theshutter 59. Thus, when the shutter 59 is rotated, the tip end of thetorsion spring 60 may be prevented from scratching and damaging the wallsurface of the container body 50 a.

When the shutter 59 is at the position, at which the recovery port 58 isclosed (the position shown in FIG. 21), the protrusion 75 protrudes by alarger length than a length of a segment that connects a contactposition between the tip end of the torsion spring 60 and the containerbody 50 a, with the terminal 60 b of the twisted part 60 a near thecontainer body 50 a in a case in which the protrusion is not provided.As long as this is satisfied, the non-contact state between the tip endof the torsion spring 60 and the container body 50 a is maintained evenif the shutter 59 is rotated.

In the above description, the powder recovery container according to theexemplary embodiment of the present invention is applied to an imageforming apparatus for recording color images. However, the powderrecovery container may be applied to an image forming apparatus forrecording monochrome images.

The foregoing description of the exemplary embodiments of the presentinvention has been provided for the purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Obviously, many modificationsand variations will be apparent to practitioners skilled in the art. Theembodiments were chosen and described in order to best explain theprinciples of the invention and its practical applications, therebyenabling others skilled in the art to understand the invention forvarious embodiments and with the various modifications as are suited tothe particular use contemplated. It is intended that the scope of theinvention be defined by the following claims and their equivalents.

1. A powder recovery container, comprising: a container body having awall surface; a reservoir chamber that stores a recovered powder; arecovery port that faces the reservoir chamber, a powder conveying unitthat conveys and recovers the powder through the recovery port beingremovably inserted into the recovery port; a pair of door panels havingrotating shafts arranged at two positions with the recovery portarranged therebetween, the door panels being rotated toward thereservoir chamber around the rotating shafts to open and close therecovery port; sealing members attached to the door panels, the sealingmembers overlapping one another between distal ends of the door panelsto seal a gap between the distal ends of the door panels when the doorpanels are located at positions, at which the recovery port is closed;and urging members that urge the door panels in a direction, in whichthe recovery port is closed.
 2. The powder recovery container accordingto claim 1, wherein the sealing members are attached to surfaces of thedoor panels that contact a peripheral edge of the recovery port.
 3. Thepowder recovery container according to claim 1, wherein the sealingmembers have a smaller length along the rotating shafts than a length ofthe door panels along the rotating shafts.
 4. The powder recoverycontainer according to claim 1, further comprising: rotating-shaftsupport members that rotatably support the rotating shafts, wherein thedoor panels have notches to avoid the door panels from interfering withthe rotating-shaft support members.
 5. The powder recovery containeraccording to claim 1, wherein an end of each of the door panels near thecorresponding rotating shaft is located at a position at a smallerdistance from the wall surface of the container body than a distance ofthe rotating shaft by which the rotating shaft is moved toward the wallsurface of the container body to be detached from the correspondingrotating-shaft support member.
 6. The powder recovery containeraccording to claim 1, wherein each of the urging member is a torsionspring having a twisted part, the urging member providing an urgingforce by using restoration of the twisted part, and wherein thecontainer body, to which one end of the torsion spring contacts with apressure, has a protrusion that maintains a non-contact state between atip end of the torsion spring and the container body when thecorresponding door panel is rotated.
 7. The powder recovery containeraccording to claim 6, wherein, when the door panel is at the position,at which the recovery port is closed, the protrusion protrudes by alarger length than a length of a segment that connects a contactposition between the tip end of the torsion spring and the containerbody, with a terminal of the twisted part near the container body in acase in which the protrusion is not provided.
 8. An image formingapparatus, comprising the powder recovery container according to claim 1attached to the image forming apparatus.